Volume 75 (2025) Issue: 2025 No#3

High level fluoroquinolone resistance and multidrug resistance in Salmonella spp. isolated from poultry, turkey floks and slaughterhouses in Algeria

Author(s): Amina Djemaioune, Dalibor Todorović,Katarina Novović, Svetlana Miković Dramlić, Zineb Cherak, Esma Bendjama, Oussama Khalouta, Bakir Mamache, Branko Jovčić, Maja Velhner, Ammar Ayachi

Keywords:poultry, Salmonella, resistotype, resistance genes, mutations.

In this work, Salmonella spp. was detected in poultry and turkey farms, slaughterhouses and hatcheries in the Sétif Province in Algeria. Eighty single isolates per farm were analyzed by establishing the resistotype and detected resistance genes underlining the mechanism of resistance. In one case, serotypes S. Virchow and S. Ivory were found in the same sample and both isolates were resistant to nalidixic acid. S. Enteritidis was detected in four broiler breeder flocks, three hatcheries, 12 flocks of layers, 12 broiler flocks while five slaughterhouses yielded 10 isolates. The wide distribution of S. Enteritidis in the primary production and food chain in Algeria requires special measures in the management practice on poultry farms. All isolates except five were resistant to nalidixic acid and pefloxacin which means that these salmonellae phenotypically express reduced sensitivity to ciprofloxacin. Five isolates were multidrug resistant. Two Salmonella Galinarum biotype gallinarum isolates from flocks of laying hens were resistant to quinolones, aminoglycosides and sulfonamides. One of these isolates was also resistant to trimethoprim alone and in combination with sulafmethoxazole. One S. Enteritidis isolate was resistant to ampicillin, nalidixic acid, pefloxacin and colistin. Especially worrying is the high level of resistance to ciprofloxacin in nine isolates (six, Salmonella Galinarum biotype gallinarum, two, S. Kentucky and one Salmonella enterica subsp. enterica isolate) due to mutations in the enzymes DNA gyrase and topoisomerase IV. Resistance genes were identified in 21 isolates. All resistance genes detected are commonly conferring resistance to ampicillin, streptomycin, gentamicin, tetracycline, sulfonamides and trimethoprim antibiotics.